Pranz,
Although I haven't heard from the grammar guru, I did check out MW--and there is this application in which
number takes the plural verb:
"(3) : an indefinite usually large total <
a number of members were absent> <the number of elderly is rising"
Now, if "of members" was understood, you'd still write "a number were absent." I think my little story about people at the Greek festival with some doing one thing during the storm and others doing something else is a good example where you could write that a number (of those people) were doing something else. The singular verb would sound horrible. "Many went to tents; some ran home; a number was busy complaining to the management." Yecch! "A number were busy complaining to the management." [And, FTR, I wasn't beginning to suggest an application of the subjunctive!
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